Change: Use extended Action1s

[glx22]

Each spriteset gets its own unique ID.
Removes the "all spritesets in a single sprite group/layout must have the same size" limitation.

Not really tested beside checking NFO output.

[andythenorth]

Works for me in test of

• nml CHIPS with unequal sized spritesets
• pre-existing Iron Horse
• pre-existing FIRS

[PeterN]

First question... what is an extended action 1?
Does this need a specific version of OpenTTD or is it an older feature that just isn't used?

[glx22]

https://newgrf-specs.tt-wiki.net/wiki/Action1#Extended_format present since OpenTTD 1.2.
The most important part is https://newgrf-specs.tt-wiki.net/wiki/Action1#first-set which allows to reduce duplication and the need for same size spriteset in a spritelayout.

[andythenorth]

Still works for me :P

[glx22]

Now includes changes from @PeterN's pr309-redux branch.

[PeterN]

I'm not sure why the examples are being changed -- presumably they don't do anything that requires this new format as they work before. Makes me think something is not quite right.

[glx22]

Examples are changed because IDs are not reused anymore.
Before the change it was always act1 starting from 0 followed by act2 (act2 only using most recent act1), now all spritesets are accessible from anywhere once defined and they get their own ID.